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7 Reasons Why Your Aircon Unit Freezes Up And How To Solve It

A leaking aircon unit has been our common home problem and oftentimes, we already know what to do to solve it. But what if suddenly your aircon unit freezes? Singapore is indeed one of the hottest countries especially during the summer but household owners would also complain and wonder as to why their aircon unit freezes. Let’s take a look at some of the reasons why this happens:

1) Frost build up

After long use of the aircon unit, water builds up in your indoor or outdoor units, causing them to freeze over, check the drainage system first because this might be clogged by leaves and other debris at the back panel of the aircon unit. Frost may appear on the back panel of the aircon unit which is normal. However, if you find it difficult to remove the frost with your bare hands then this means that there is an aircon issue.

Pro 338 Solution: You can try unplugging the aircon unit for several minutes and clear out any ice build-up inside before turning it back on. But if you are still unable to resolve this aircon issue, you should contact a professional aircon servicing company as there might be an underlying issue with your aircon unit.

The most common reason why your aircon unit freezes are because of a faulty thermostat. If you find that the aircon unit is turning off and on too frequently or it doesn’t turn on at all, this means that there’s a certain aircon issue with the thermostat.

Pro 338 Solution: You can try replacing it but if it still doesn’t work then you might need to buy a new aircon unit altogether as it might be broken.

If you are using a portable aircon unit, the reason why it freezes up is because of too much humidity which causes ice to form on top of it. Make sure that the vents face outward so that they don’t get blocked by ice when unnecessary humidity accumulates inside them.

Pro 338 Solution: You can also try cleaning your air filter regularly with water and vinegar to remove any dust build-up inside.

4) Clogged drainage pipe

If there are lots of ice particles accumulating at the back or bottom panel of your aircon units then this usually means that there is a problem with the drainage system leading water to accumulate and freeze.

Pro 338 Solution: You can try removing this by hand but it’s very dangerous so you need a professional aircon servicing company if possible since this is also a meticulous type of work.

5) Faulty wirings

Another possible cause for your aircon unit freezing is broken wiring leading to the malfunction of the compressor. These are complicated parts to reach so it is not recommended that you do some DIY Hacks to repair it.

Pro 338 Solution: In cases like this, it’s best to contact a professional aircon servicing company as they will have the necessary tools to fix or replace faulty parts on your aircon unit safely.

In case your aircon unit freezes, you need to check if the aircon unit itself is faulty. In short, it may be a sign of a low refrigerant level in the system or an open heat source. You can also have a hole or mismatch between the indoor and outdoor units.

Pro 338 Solution: Try turning off the power supply to your aircon unit and use a multimeter on the Refrigerant Leak setting. Find the low-pressure cutout switch and jumper it with a piece of wire. If you are able to measure refrigerant, then any of these options may help you fix the aircon issue but if not, then it’s better to call for a professional aircon servicing company’s help in order to be able to do it right.

Freezing can also occur due to inadequate captive air volume (CAV), poor ventilation, and hot outdoor ambient temperature conditions which means that it will be able to reach close proximity with your aircon unit outdoor heat exchanger coils even though they are indoors. The reason why hot outdoor ambient temperature makes this more severe is that it contributes towards thermal runaway where your aircon compressor has to work harder on cooling down the room instead of dehumid resulting in high pressure on refrigerant.


It’s always a good time to talk about the common issues that aircon units have. This way, you’ll be able to spot if there are problems with your unit or not and prepare for its replacement accordingly. If you require our aircon servicing services, Whatsapp us at +65 9222 4141 for a fast and transparent quote.

338 Aircon Servicing Singapore provides an extensive range of Aircon Services including Aircon Servicing, Aircon Repairs, Aircon Installation of the best aircon brands, Chemical Overhaul, Gas Top-up, Aircon Leaking Water, and Aircon Not Cold Fix, and more. We have a team of professional technicians who are equipped with vast knowledge and experience in the Aircon industry.

We have over 15 years of experience in dealing with aircon works and have completed thousands of aircon works for both residential (Landed, Condo, and HDB) and commercial. We are a highly recommended Aircon Company in Singapore, with many delighted customers and reviews over the years on Google and Facebook.

WhatsApp us at +65 9222 4141 for a transparent quotation and honest pricing for all your aircon needs or Call us at +65 9222 4141. We offer a fast and efficient service to serve any of your aircon needs!


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